The identification of most clinical isolates of yeasts other than Candida albicans currently takes at least 24 hours from the time of isolation. Newer methodologies may significantly shorten this period. The MicroScan Yeast Identification Panel (Baxter Healthcare Corporation, MicroScan Division, West Sacramento, CA) is one such new methodology, intended to allow yeast identification in four hours from the time sufficient growth is obtained. The purpose of this study is to assess the accuracy and clinical usefulness of this procedure for the identification of yeast isolates. Initial studies have suggested that this system will not prove adequate for accurate identification of clinical isolates of yeast species, but some further study will be needed adequately to document this initial impression. Our studies have indicated that this methodology in its current state of development does not provide sufficient accurate yeast identification for the needs of our laboratory.